To pull with your lats and anterior deltoids, you have to engage your ring and pinky fingers. Try it. Put your first two fingers, your index and middle fingers, with your elbow higher than your hand on a table and push. You feel the front of your shoulder. Now try the last two fingers, your ring and pinky. Press on the table and you will feel your lats and the muscles in the back of your shoulder engage. So we designed paddles to give more resistance to that part of your hand. Supination paddles put more force on the last two fingers and have the additional benefit of building feel for the water in the rest of the hand. Using ultralight aluminum also allows for flex when the swimmer gets the proper hand and arm pitch. This not only balances the stroke; it takes pressure off the rotator cuff and makes stronger faster more enduring strokes possible. We also have two different models, the full arm model and the hand model. Both have their specific benefits. Supination Paddles were inspired by a conversation with Berkeley coach Nort Thornton and Coach Steve Friederang at the 2012 ASCA Convention. Nort we hope you like how we took your whiffle ball idea a step further.